The perceptual and acoustic characteristics of Japanese elderly speech—The relationship between cognition and speech motor performance

Abstract

Recent studies showed the evidences that language complexity or cognitive load may deteriorate the speed and accuracy of speech. No study was found to explore the relationship between cognitive load and speech movement directly from the perspective of working memory (WM) capacity. In Reading Span Test (RST), WM capacity would be reduced for speech production as the number of sentences and target words increased. The aim of our study is to reveal perceptual and acoustic characteristics of the elderly speech in relation to WM capacity. It was hypothesized that slower speech rate and/or slurred speech would be observed for elderly adults with reduced WM capacity or low cognitive function. Twelve elderly adult speakers of Japanese participated in this study. The scores of Montreal Cognitive Assessment Japanese version was used to divide the participants into high and low cognitive groups. For RST, each participant was asked to read visually presented sentence(s) aloud and to recall target word(s). Reading performances were recorded by a microphone being set in front of each participant for later acoustic evaluations. The reading performances of two cognitive groups were compared and results regarding on the presence of slower speech rate and slurred speech, judged by experienced speech language pathologists, were presented. We will discuss the relationship between the cognitive load and speech movement in the elderly based on the acoustic evaluation.